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1.
庞家河微细浸染型金矿金的赋存状态   总被引:1,自引:0,他引:1  
本文论述了庞家河金矿矿石中的主要在金矿物和载金矿物,金然矿石中的配分微型赋存状态矿石中金矿物主要有自然金银金矿;主要载金矿物是黄铁矿,毒砂和粘土质矿物(含绢云母和少量粉砂质)金主要为次显微金,粒度在0.025~0.1μm之间,呈小圆球状及链状的独立金矿物(自然金)充填在黄铁矿,毒砂的微裂隙度或沉淀在晶面上或吸附在晶体边缘。在氧化或半氧化矿石中,可见到一部分可见金或显微金。  相似文献   

2.
陕西镇安丘岭,二台子金矿床富砷矿石中金的赋存状态   总被引:2,自引:0,他引:2  
对丘岭、二台子微细浸染型金矿床中-高含金样品的光学、背散射电子、二次离子和高分辨透射电镜图象分析表明,金与砷具有显微尺度的强相关性。金和砷主要赋存于含砷黄铁矿增生体、毒砂和砷黝铜矿之中。已发现金一般呈微米级小圆球存在于含砷硫化物中。次显微金在高异常区的沉淀作用是如此之迅速,其以微细自然金颗粒存在于砷的硫化物中。  相似文献   

3.
水银洞超大型金矿床金赋存于沿沉积型自形半自形黄铁矿内核生长成的含砷黄铁矿环带中。近来从水银洞金矿床原生富矿石(碳酸盐岩型矿石)中一条含砷黄铁矿细脉中发现100余粒次显微-显微自然金颗粒(0.1~6μm),通过对金的赋存状态及预氧化提金后尾渣的研究,认为矿石破磨至325目有可能损失部分金和系统中黄铁矿出现过氧化现象,从而...  相似文献   

4.
云南金厂箐金矿金的赋存状态及工艺特性研究   总被引:1,自引:0,他引:1  
应用矿相显微镜、电子探针、X射线衍射仪和化学物相分析等测试手段,研究了金厂箐金矿中金及有害元素砷的赋存状态。金主要为次显微粒和显微粒自然金,多以包裹体形式散布于毒砂和黄铁矿为主的载金矿物中,毒砂和黄铁矿主要以自形、半自形晶状态产出,少部份呈极细粒状(<10μm)包裹于脉石矿物中;矿石中有害元素砷主要以毒砂和含砷黄铁矿的矿物形式存在。本文还对矿石工艺特性进行了研究,为选冶试验及其生产工艺提供了必要依据。  相似文献   

5.
彭达铨 《河南地质》1995,13(2):87-90
川西北地区微细浸染型金矿床,主要产于具轻微变质的沉积岩地层中,矿石中除见极少中一细粒显微状自然金外,金主要呈超(次)显微状赋存于含金矿物中;矿石中与黄铁矿,辉锑矿,雄黄等紧密共生的毒砂,呈针状和梭状,低显微硬度,矿物成分以富硫讽的盆砷,并含金贫解及多种杂质元素。成分复杂的含金低温型毒砂,为寻找该类型金矿的标志矿物之一,并具有成因标型意义。  相似文献   

6.
青海五龙沟金矿床矿石、矿物含金性及金的赋存状态   总被引:2,自引:0,他引:2  
本文采用矿相显微镜研究、金溶解性试验、化学分析、背散射电子面扫描、二次电子面扫描、晶体X射线衍射等手段对青海五龙沟金矿床矿石、矿物的含金性及金的赋存状态进行了研究。结果表明,多次叠加蚀变及黄铁绢英岩化毒砂伦金矿石含金较高,金主要以超显微状态存在于毒砂、含砷黄铁矿等金矿硫化物中,存在形式可能为小于10.0nm的非晶格金状态,矿石及矿物中典型元素组合为Au-As-Sb.  相似文献   

7.
<正>黔西南微细浸染型(卡林型)金矿矿石类型包括原生矿石,蚀变矿石,氧化矿石及红土型矿石。其中原生矿石是典型难浸难处理金矿石,金主要以"不可见金"形式赋存于毒砂和含砷黄铁矿中。蚀变型矿石中往往存在微细粒自然金(呈  相似文献   

8.
烟台南张家金矿毒砂的标型特征   总被引:3,自引:0,他引:3  
烟台南张家金矿是通过查证砷异常发现的,在矿石中发现了大量毒砂。通过对该金矿毒砂的产状、形态、成分和热电性的研究,认为该矿毒砂形成于中低温环境,可能含超显微金,矿区异常主要由毒砂引起民。  相似文献   

9.
在对美国卡林硫化物金床和俄罗斯五月金矿床详细研究的基础上,指出两个含金-硫化物金矿床都与低温金-银,锑-汞和汞矿床共生。矿石中的金主要是细分散金并在针状砷黄铁矿中的形成亚微细包体。分析两个矿床的矿石成分,不难看出在含金量和造岩地元素上也有一系列相似之处,从有机碳含量到含矿交代岩中钾,钠状态都如此,从外表看,它们都必于沉积或者热液-沉积成矿。在储量方面,细分散型矿石的含金矿床往往是大型或越大型矿床,  相似文献   

10.
为合理制定提金工艺及高效回收金,采用光学显微镜下鉴定,结合化学分析、X射线衍射(XRD)、X射线光电子能谱(XPS)及电子探针X射线显微分析(EPMA)等手段,研究了贵州某卡林型金矿的载金矿物特征及金赋存状态。结果表明,矿石含金4.30 g/t,w(S)、w(As)分别为2.97%和0.35%。S、As主要以-1价态存在,说明矿石为原生金矿。矿石主要为粒状、草莓状、生物假象、交代和条带状结构,矿石中主要硫化物为含砷黄铁矿和毒砂,主要脉石矿物为石英、碳酸盐矿物和绢云母等。含砷黄铁矿多与石英和碳酸盐矿物连生,少数被隐晶质石英和炭泥质包裹,部分呈环带或弯曲状生物遗迹特征。94.88%的金以包裹金形式存在,含砷黄铁矿为主要载金矿物,其中金分布率为75.81%。不同形态的含砷黄铁矿中Au含量高低为:细粒状>生物碎屑状>草莓状>粗粒状,Au-S、Au-As之间均无正相关性。含砷黄铁矿中均赋存有晶格金和纳米金颗粒,金整体呈不均匀稀疏浸染状分布。研究结果可为贵州及其它地区卡林型金矿预处理-浸金工艺的制定提供理论指导,有效氧化或破坏载金含砷黄铁矿和石英包裹体及防止预处理过程中金的二次包...  相似文献   

11.
秦岭卡林型金矿床金、砷地球化学探讨   总被引:16,自引:0,他引:16  
讨论了秦岭卡林型金矿床中Au 、As 的元素地球化学、矿物学特征。在含矿岩系中获得的Au、As 等成矿元素初始含量较高,且主要集中在成岩黄铁矿中。在矿石样品中对含砷硫化物矿物的研究表明,Au 、As 在矿物显微结构中具有强的正相关性。在大量金进入到硫化物结构之前,就已有[AsS]3 - 的存在。在含砷硫化物矿物中,金多半以一种带电类型(Au3 +) 存在, 它很可能替代铁位置上的过剩砷, 以固溶体方式沉淀于硫化物矿物中。此时, 黄铁矿构成(Au3 + ,Fe2 +)([AsS]3 - [S2]2 - ),毒砂构成(Au3 + ,Fe2 +)([AsS]3 - [AsS]3 -) 。通过电子探针(EMP) 和透射电镜(TEM) 对秦岭卡林型金矿含砷硫化物矿物中金的赋存状态的研究表明,在金的成矿作用早期阶段, 金主要以固溶体形式优先富集于含砷黄铁矿和毒砂及砷黝铜矿之中,并且认为是以金的氧化和砷的还原的共沉淀方式发生的。在此之后的金成矿作用晚期阶段,由于热液蚀变和结晶作用程度的增高,寄主矿物耐熔性质相对降低,加之金本身的聚集能力,和因过量砷加入而造成的含砷硫化物矿物的晶格缺陷,致使已形成的固溶体金以“出溶”形式发生再分布,赋存于硫化物矿物晶粒  相似文献   

12.
Mineral assemblages, chemical compositions of ore minerals, wall rock alteration and fluid inclusions of the Gatsuurt gold deposit in the North Khentei gold belt of Mongolia were investigated to characterize the gold mineralization, and to clarify the genetic processes of the ore minerals. The gold mineralization of the deposit occurs in separate Central and Main zones, and is characterized by three ore types: (i) low‐grade disseminated and stockwork ores; (ii) moderate‐grade quartz vein ores; and (iii) high‐grade silicified ores, with average Au contents of approximately 1, 3 and 5 g t?1 Au, respectively. The Au‐rich quartz vein and silicified ore mineralization is surrounded by, or is included within, the disseminated and stockwork Au‐mineralization region. The main ore minerals are pyrite (pyrite‐I and pyrite‐II) and arsenopyrite (arsenopyrite‐I and arsenopyrite‐II). Moderate amounts of galena, tetrahedrite‐tennantite, sphalerite and chalcopyrite, and minor jamesonite, bournonite, boulangerite, geocronite, scheelite, geerite, native gold and zircon are associated. Abundances and grain sizes of the ore minerals are variable in ores with different host rocks. Small grains of native gold occur as fillings or at grain boundaries of pyrite, arsenopyrite, sphalerite, galena and tetrahedrite in the disseminated and stockwork ores and silicified ores, whereas visible native gold of variable size occurs in the quartz vein ores. The ore mineralization is associated with sericitic and siliceous alteration. The disseminated and stockwork mineralization is composed of four distinct stages characterized by crystallization of (i) pyrite‐I + arsenopyrite‐I, (ii) pyrite‐II + arsenopyrite‐II, (iii) galena + tetrahedrite + sphalerite + chalcopyrite + jamesonite + bournonite + scheelite, and iv) boulangerite + native gold, respectively. In the quartz vein ores, four crystallization stages are also recognized: (i) pyrite‐I, (ii) pyrite‐II + arsenopyrite + galena + Ag‐rich tetrahedrite‐tennantite + sphalerite + chalcopyrite + bournonite, (iii) geocronite + geerite + native gold, and (iv) native gold. Two mineralization stages in the silicified ores are characterized by (i) pyrite + arsenopyrite + tetrahedrite + chalcopyrite, and (ii) galena + sphalerite + native gold. Quartz in the disseminated and stockwork ores of the Main zone contains CO2‐rich, halite‐bearing aqueous fluid inclusions with homogenization temperatures ranging from 194 to 327°C, whereas quartz in the disseminated and stockwork ores of the Central zone contains CO2‐rich and aqueous fluid inclusions with homogenization temperatures ranging from 254 to 355°C. The textures of the ores, the mineral assemblages present, the mineralization sequences and the fluid inclusion data are consistent with orogenic classification for the Gatsuurt deposit.  相似文献   

13.
黔东南金成矿区位于江南造山带金成矿省的西南端,成矿条件优越。坑头金矿床是黔东南金成矿区的一个中型矿床,在其深部找矿中,发现除石英脉型矿体外,还存在蚀变岩型矿体。然而,这种蚀变岩型矿体的构造形态、蚀变类型、与石英脉型矿体之间关系和金的赋存状态尚不清楚。本研究与当前的勘查工作紧密结合,围绕石英脉型矿体和新发现的蚀变岩型矿体为研究切入点,借助微区分析技术(扫描电镜和电子探针)进行系统的“流体- 蚀变- 成矿”研究。蚀变矿物金红石矿物化学显示为热液成因,具有典型造山型金矿床的金红石标型特征。围岩的沉积- 成岩过程(包括低级变质作用过程),主要形成了草莓状黄铁矿和含铁碳酸盐岩,为后期含金硫化物(黄铁矿和毒砂)的形成提供物质基础(如Fe)。金的成矿富集过程主要经历了绢云母+毒砂+黄铁矿+石英(Ser+Apy+Py+Qtz)阶段、黄铁矿+毒砂+石英(Py+Apy+Qtz)阶段和自然金+石英(Au0+Qtz)阶段。在Ser+Apy+Py+Qtz阶段,主要表现为含矿流体与围岩的初级交代,形成大量浸染状黄铁矿+毒砂的硫化带;Py+Apy+Qtz阶段主要为流体沿着剪切带再交代,形成蚀变岩型矿体;Au0+Qtz阶段主要表现为含金石英大脉的形成。金的赋存状态研究显示,蚀变岩矿体中Au以他形显微- 次显微自然金赋存在蚀变岩硫化物裂隙中,或以化学结合态方式赋存在黄铁矿和毒砂中(后者占主导)。在晚期Au0+Qtz阶段,自然金呈自形、粗粒(~0. 5 mm)赋存在石英脉中。综合研究认为,多期构造(流体)交代导致的溶解- 再沉淀可能是坑头金富集成矿主要原因之一。  相似文献   

14.
笔者认为新发现的川西北某金矿床与热液浸染交代的卡林型金矿床类型可以类比,成矿受断裂、破碎带控制;赋矿层主要为危关群泥灰岩;自然金呈微细粒和显微细粒赋存于黄铁矿、毒砂及褐铁矿之中。矿石氧化程度高,杂质含量低,易选治。  相似文献   

15.
Mineral assemblages and chemical compositions of ore minerals from the Boroo gold deposit in the North Khentei gold belt of Mongolia were studied to characterize the gold mineralization, and to clarify crystallization processes of the ore minerals. The gold deposit consists of low‐grade disseminated and stockwork ores in granite, metasedimentary rocks and diorite dikes. Moderate to high‐grade auriferous quartz vein ores are present in the above lithological units. The ore grades of the former range from about 1 to 3 g/t, and those of the latter from 5 to 10 g/t, or more than 10 g/t Au. The main sulfide minerals in the ores are pyrite and arsenopyrite, both of which are divisible into two different stages (pyrite‐I and pyrite‐II; arsenopyrite‐I and arsenopyrite‐II). Sphalerite, galena, chalcopyrite, and tetrahedrite are minor associated minerals, with trace amounts of bournonite, boulangerite, geerite, alloclasite, native gold, and electrum. The ore minerals in the both types of ores are variable in distribution, abundance and grain size. Four modes of gold occurrence are recognized: (i) “invisible” gold in pyrite and arsenopyrite in the disseminated and stockwork ores, and in auriferous quartz vein ores; (ii) microscopic native gold, 3 to 100 µm in diameter, that occurs as fine grains or as an interstitial phase in sulfides in the disseminated and stockwork ores, and in auriferous quartz vein ores; (iii) visible native gold, up to 1 cm in diameter, in the auriferous quartz vein ores; and (iv) electrum in the auriferous quartz vein ores. The gold mineralization of the disseminated and stockwork ores consists of four stages characterized by the mineral assemblages of: (i) pyrite‐I + arsenopyrite‐I; (ii) pyrite‐II + arsenopyrite‐II; (iii) sphalerite + galena + chalcopyrite + tetrahedrite + bournonite + boulangerite + alloclasite + native gold; and (iv) native gold. In the auriferous quartz vein ores, five mineralization stages are defined by the following mineral assemblages: (i) pyrite‐I; (ii) pyrite‐II + arsenopyrite; (iii) sphalerite + galena + chalcopyrite; (iv) Ag‐rich tetrahedrite‐tennantite + bournonite + geerite + native gold; and (v) electrum. The As–Au relations in pyrite‐II and arsenopyrite suggest that gold detected as invisible gold is mostly attributed to Au+1 in those minerals. By applying the arsenopyrite geothermometer to arsenopyrite‐II in the disseminated and stockwork ores, crystallization temperature and logfs2 are estimated to be 365 to 300 °C and –7.5 to –10.1, respectively.  相似文献   

16.
甘肃阳山金矿床含砷黄铁矿及毒砂的XPS研究   总被引:9,自引:4,他引:5  
杨荣生  陈衍景  谢景林 《岩石学报》2009,25(11):2791-2800
阳山金矿是西秦岭地区新发现的超大型金矿.载金矿物中元素的赋存状态是认识成矿机理、评价矿床采选冶过程对环境影响的重要依据.作者运用XPS技术测定了载金矿物含砷黄铁矿和毒砂新鲜断裂面的As3d、Fe2p及S2p的存在形式和相对原子百分含量.结果表明,在含砷黄铁矿表面,超过50%的As以As~(-1)形式存在,约18%~20%的As以As~(3+)形式存在,约30%的As以As~(5+)形式存在.在毒砂表面,超过60%的As以As~(1-)形式存在,约30%的As~(3+)形式存在,其余10%的As主要以As~(3+)形式存在.分析证明As、Fe、S等元素在含砷黄铁矿和毒砂中主要以As`(1-)、Fe~(2+)、S~(1-)形式存在外,As元素可能还以As~(3+)形式存在于含砷黄铁矿及毒砂结构中.  相似文献   

17.
Ye MyintSwe    Insung Lee  Than  Htay Min  Aung 《Resource Geology》2004,54(2):197-204
Abstract. Gold mineralization at Kyaukpahto occurs as a stockworks/dissemination style with localized breccia zones in silicified sandstones of the Male Formation (Eocene). The mineralization appears to be closely associated with NNE-SSW trending extensional faults probably related directly to the dextral movement of the Sagaing Fault system. Intense silicifica-tion associated with sericitization, argillic alteration and decalcification is recognized in the Kyaukpahto gold deposit. The important ore minerals associated with the gold mineralization are pyrite, arsenopyrite and chalcopyrite with minor amounts of other sulfides. Gold occurs as free particles or locked with pyrite, arsenopyrite, chalcopyrite and tetrahedrite. Silver, copper, arsenic and antimony particularly appear to be good pathfinders and the best geochemical indicators of gold mineralization at Kyaukpahto. Electron microprobe analysis indicates that the fineness for the native gold ranges from 844 to 866. Present geological, mineralogical and geochemical investigations demonstrate that the Kyaukpahto gold deposit has been formed as a result of hydrothermal processes in a shallow level epithermal environment.  相似文献   

18.
The Song Hien rift basin is considered to be one of the most important regions of gold mineralisation in North East Vietnam. A number of gold deposits in the Song Hien rift basin are hosted in Triassic and Devonian sedimentary formations of the basin. The largest among them are the Bo Va, Tham Riem and Khung Khoang deposits. The Bo Va deposit is hosted in carbonaceous sedimentary rocks of Triassic age, whereas the Tham Riem and Khung Khoang deposits are hosted in carbonaceous sedimentary rocks of Devonian ages. Based on the mineral composition of the ores, the deposits can be divided into to two types: (i) pyrite dominated and (ii) pyrite-arsenopyrite dominated. The Khung Khoang is of the first type and the Bo Va and Tham Riem deposits belong to the second type. The isotopic composition of pyrite and arsenopyrite in the Tham Riem deposit however, is close to that for the ores of the Bo Va deposit. The δ34S value for pyrite ranging from −3.7‰ to −7.4‰ and for arsenopyrite ranging from −3.2‰ to 7.4‰. The δ34S of pyrite in the ore from the Khung Khoang deposit however, has a much heavier isotopic composition of +18.9 to +20.2‰. A narrow range of the variation of sulfur isotopic composition of pyrite and arsenopyrite, the presence of visible gold as inclusions, the presence of chalcopyrite, sphalerite and other inclusions in arsenopyrite and pyrite, the large size of the grains of major ore minerals allow us to assume that the primary gold ores of the Bo Va and Tham Riem deposits underwent metamorphic transformations. The absence of arsenic, antimony, mercury and other characteristic elements in the ores of the Khung Khoang deposit, and substantially heavier isotopic composition of sulfur similar to the sulfur isotopic composition of marine sulfates in the Devonian, allow us to assume another source of the ore components, not connected with the Triassic sedimentary rocks of the Song Hien rift.  相似文献   

19.
加吾金矿位于青海省东部同德县境内,是武警黄金部队近年来发现的又一处具大型规模的金矿床。该矿床在大地构造位置上处于西秦岭与东昆仑的衔接部位。矿体赋存于中下三叠统中,在平面上呈舒缓波状,在剖面上为脉状、似层状。矿石中金属矿物主要为黄铁矿和毒砂,金主要以微细粒分布于石英裂隙和毒砂、黄铁矿等矿物粒间。区内中下三叠统隆务河群板岩中的金丰度值和有机碳含量高,是有利的赋矿层位。矿体产于北西向和近东西向构造蚀变带内,受区内断裂带控制明显。矿体在空间上与印支期中酸性岩浆岩相伴产出。研究表明,该矿床为受构造蚀变带控制的、与沉积作用和岩浆活动有成因联系的微细浸染型金矿床。截止目前,该矿共计探明金矿脉22条,累计提交金资源量超过20t。该矿的发现和评价对指导青海东部微细浸染型金矿找矿具有重要的示范意义。  相似文献   

20.
西准噶尔宝贝金矿地质与容矿火山岩的锆石SHRIMP年龄   总被引:35,自引:0,他引:35  
位于西准噶尔的宝贝金矿主要由石英脉型矿石组成,主要含金矿物为银金矿,以裂隙金和包裹金的形式赋存在毒砂、黄铁矿和石英中。宝贝金矿的黄铁矿普遍含As(最高达3.88%,平均1.49%)。根据脉穿切和矿物共生组合可将宝贝金矿的成矿作用划分出四个成矿阶段:钠长石–石英阶段(I)、银金矿–黄铁矿–毒砂–石英阶段(II)、多金属硫化物浸染状矿化阶段(III)和碳酸盐化阶段(IV),其中第II和III阶段为主要成矿期。利用锆石SHRIMP方法测定了赋矿围岩(酸性凝灰岩)的形成时代,其U–Pb谐和年龄为328.1±1.8 Ma(MSWD=1.6, n=13)。该年龄代表宝贝金矿赋矿围岩的形成时间,即西准噶尔地区大规模中酸性火山岩的喷发时间。  相似文献   

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